Warning lamp



FIG. 1 is a top plan view of a warning lamp showing my new design, the bottom plan view being a mirror image thereof;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a right side elevational view thereof, the left side being a mirror image thereof; and,

FIG. 4 is a rear elevation view thereof.

The broken lines are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a warning lamp, as shown and described. 